Isothermal vapor-liquid equilibrium (VLE) data are presented for the system ethylene + decafluorobutane. Measurements are performed for four isotherms around the critical temperature of ethylene, i.e. in the temperature range from 268.13 to 298.13 K. The measurements are undertaken using a "static-analytic" type apparatus, sampling the phases in equilibrium via a moving capillary sampler (ROLSI (TM)). The uncertainties of the present measurements of temperature, pressure and mole fraction are within 0.036 K, 0.0058 MPa and 0.02 mol/mol, respectively. The VLE data are correlated with the Peng-Robinson equation of state (PR EOS), incorporating the Mathias-Copeman alpha function. Both, the Wong-Sandler mixing rule with the non-random two-liquid (NRTL) activity coefficient model and the quadratic Van der Waals one-fluid mixing rule are used. In addition, a new rigid force field model for decafluorobutane is developed and molecular simulations are carried out. The simulation results are compared to the present experimental data for the binary system. Furthermore, pure component properties of decafluorobutane are predicted and compared to experimental data from the literature and the PR EOS. (c) 2012 Elsevier B.V. All rights reserved.